Millions of PCs are presently in use. Each PC includes various hardware components including a CPU, keyboard, mouse, video display adapter card/circuit (hereinafter referred to as “VDAC”), video display monitor (hereinafter referred to as “VDM”), and/or one or more mass storage devices. Other special purpose hardware devices such as a modem, voice or sound card, or network interface adapter card may be connected to or installed within a PC.
Presently, a VDM is normally either an analog or TTL (digital) display device that connects to either a 15 pin or 9 pin receptacle on a PC's VDAC. A PC's VDAC normally sends video signals to a VDM in either a monochrome, CGA, EGA, or VGA format known to persons familiar with the trade. The present invention, however, is not to be limited to these video formats and will operate with any video format when properly configured. PC's may be accessed and controlled remotely by other PC's by essentially two different types of processes. First, a hardware network interface adapter card or device may be installed or connected to a PC. This interface device is then connected, either using a cable or through the airways using a wireless network interface device, to other PCs attached to a Local Area Network (LAN). All such devices require Host CPU support (via network interface software installed in the PC's memory) to permit a Remote PC to access or control a Host PC. Persons familiar with the trade refer to this type of process as “peer to peer” PC networking.
Second, a memory resident software system may be installed on a Host PC having access to a modem which would then permit the Host PC to be remotely controlled over standard telephone lines by another Remote PC having access to a modem and compatible memory resident interface software operating on the Remote PC. Again, in this case the ability of the Remote PC to control and access the Host PC depends on CPU processing support being provided by both PC's and a memory resident software system being pre-installed on the Host PC to acknowledge and process an incoming call from the Remote PC.
In many cases control of a PC is not always practical or possible remotely. Many PC based application software systems take over a PC completely and, due to memory restrictions or other processing conflicts, cannot co-exist with those software systems permitting Remote PC access. Moreover, even in cases where the required Host and Remote access interface software has been successfully installed, if the Host processor should lock-up or otherwise fail, remote users immediately lose their ability to access the Host system. In such cases the Remote user would not be able to remotely access information displayed on the Host PC's VDM screen after the lock-up occurred. Information displayed on the VDM screen, however, usually indicates why the failure occurred and the status of processing at the point of failure, and therefore can be particularly useful in analyzing the PC failure and in preventing future similar failures.
Numerous PC monitoring systems are presently available to automatically alert designated persons via pagers, pre-recorded voice alerts or electronic mail when a PC or application running on a PC has failed. When such failures occur, the persons being notified may be in remote locations (e.g. at home) not able to physically access the PC that has failed.
After a failure alert is issued, persons alerted typically have access to a Remote PC, but may not be able to access a desired Host PC because the Host CPU has locked up and will no longer respond to user input, the application running on the Host system does not support or condone Remote PC access, or the Host system does not have the required software installed to permit a Remote PC to access the Host PC. When a Host CPU has locked up or a program error has occurred, vital information, as to the exact nature of the problem which has occurred is often displayed on the PC's VDM screen. Normally, this information must be viewed and/or analyzed before corrective action can be taken. Devices presently exist that permit a PC to be remotely or automatically re-booted, which in many cases restores normal processing after an alert is issued. However, persons alerted are reluctant to use such devices without first looking at the PC's VDM screen to determine what may have caused the failure, so that similar failures can be prevented. In other cases, information on the VDM screen may be necessary to successfully re-start an application that has failed from the point of failure.
Many PC users need to remotely monitor and control another PC, where, due to processing restrictions or limitations, it may not be possible to use the PC's processor to access a particular PC remotely. For example, for security reasons, a bank may wish to discreetly monitor PC usage by tellers or loan officers from a central, off-site location. As a second example, a Network Manager may wish to periodically remotely monitor and control the activities of a dedicated network file server or tape backup workstation. As a third example, unskilled on-site PC users may need a simple means to permit PC maintenance personnel to have extensive remote access to their PCs, and particularly to a network file server, in the event of trouble or failure.
Numerous software systems are available which are designed to link one PC with other PCs using modems connected via standard telephone lines. These systems permit a Host PC to be controlled by a Remote PC. Special functions keys and menus are used by these software systems that permit these products to operate a Host PC from a Remote PC as if the remote user was physically sitting at the Host PC. Examples of such packages include Crosstalk, developed by Digital Communications Associates, Inc., 1000 Alderman Dr., Alpharetta, Ga. 30202-1000 (404-442-4000); Procomm Plus, developed by Datastorm Technologies Inc., 3212 Lemone Blvd, Columbia, Mo. 65201, (314-443-3282); or Unicom, developed by Data Graphics, P.O. Box 58517, Renton, Wash. 98058 (206-432-1201). Each of these products require processing support and memory from the Host PC and will halt if Host processing should lock-up or fail. Also, if these products are not pre-installed on the Host PC, remote access will not be possible and no provision is made by these products to save VDM screen history or to capture an active VDM screen when a PC has locked-up. Finally, these products assume software based control of the keyboard and/or mouse, as opposed to assuming physical control over the PC's keyboard and/or mouse, which is less restrictive.
Network software utility programs exist that permit one workstation to access and control the activities of another workstation connected to the network. Products that tall into this category include, Carbon Copy for LANs, developed by Microcom Inc., 500 River Ridge Drive, Norwood, Mass. 02062 (617-551-1000); and Map Assist, developed by Fresh Technology Company, 1478 North Tech Boulevard, Suite 101, Gilbert Arizona, 85234 (602-497-4200). Similar to the other remote access utility programs, these products require software resident in the Host PC's memory to operate. Neither remote control or access will be possible if the Host PC should lock-up or fail.
Utility software programs exist that are designed to convert graphics image data captured by document scanners into text data, so that the resulting text data can be manipulated and edited using word processing software products. Examples of such programs include, OmniPage Professional, developed by Caere Corp, 100 Cooper Ct., Los Gatos, Calif. 95030 (408-395-7000); Perceive, developed by Ocron, 3350 Scott Blvd., #36, Santa Clara, Calif. 95054; TypeReader, developed by ExperVision Inc., 3590 N. First St., San Jose, Calif. 95134 (408-428-9444); and WordScan Plus, developed by Calera Recognition Systems, 475 Potrero Ave., Sunnyvale, Calif. 94086 (408-720-8300). Such programs obtain source input data from digitized output of static data files created by document scanners as opposed to capturing, decoding then converting to text the output signals of a PC's video display adapter cards/circuits (VDAC) as the signals are occurring (i.e. on a real time basis). In addition, such utility programs depend on CPU support from the PC where they are installed, cannot transmit data related to the status of processing in the event the PC should fail, and provide for no remote keyboard and/or mouse control.
Devices exist that permit using a central keyboard and monitor to control and access multiple PC's. Examples of such products include Commander, developed by Cybex Corporation, 2800-H Bob Wallace Ave. Huntsville, Ala. (205-534-0011); Master Console developed by Raritan Computer, Inc., 10-1 Ilene Court, Belle Mead, N.J. 08502; and Plex developed by Data Vision Inc., 370 West Camino Gardens Blvd, Boca Raton, Fla., 33432 (407-482-3996). These products require the keyboard and PC interface cables to be directly connected to one or more physical cable switching device(s). The VDAC signals are merely boosted and transferred as video signals over direct dedicated cabling. No attempt is made to convert the signal output of the VDAC to a digital form suitable transmission over public utility telephone lines or other communication network. Similarly, the keyboard used by the central unit is connected directly to each PC controlled with local wiring and no attempt is made to control keyboards using the public telephone system or to support keyboards existing at both the remote console and Host PC.
Devices exist that transmit a composite (TV) video signal over a telephone line. Such products include the PhoneViewer, distributed by Home Automation Lab, 5500 Highlands Pkwy, Suite 450, Smyrna, Ga. 30082-5141 and AT&T's video phone, developed by AT&T, 14250 Clayton Road, Baldwin, Mo. 63011, 1-800-437-9504. These products rely on a video camera to periodically capture a picture which is then transmitted to a screen on the remote caller's video phone. These systems convert the video camera images captured to bit-mapped graphical images. No attempt is made to decode the data captured into text data. Furthermore, such products are not capable of decoding and transmitting the video signals produced by a PC's VDAC. If such products were used to simply snap a picture of the PC's VDM screen, the resulting data transmitted would be slow and of a poor quality, particularly if the PC video output changed during the period when the video snapshot is being; taken. Moreover, none of these products provide a PC keyboard/mouse telephone interface necessary to control a Remote PC. Even if such an interface were provided, the user may require a separate phone line to access the Remote PC, so as to not interfere with the transmission of video graphics image data derived from the composite video snapshot.
Devices exist that permit a video signal to be captured by a PC from an external analog video recording device, such as a video camera, and the signal converted into a digital format suitable for display on a PC's VDM using a video capture adapter card inserted into a PC. One such device is the Smart Video Recorder manufactured by Intel Corp., P.O. Box 58130, Santa Clara, Calif. 95052 (800-955-5599). Such devices require a dedicated cable to be directly connected from the video capture adapter card to the video recording device, and none of these products provide a PC keyboard/mouse telephone interface necessary to control a Remote PC.
Numerous devices exist that permit a PC to be re-booted remotely such as the Sentry Remote Power Manager, developed by Server Technology, 2332-B Walsh Ave. Santa Clara, Calif. 95051 (408-988-0142), Tone Operated Switch (TOPS) developed by Black Box Corp., P.O. Box 12800, Pittsburgh Pa. 15241 (412-746-5530) or TELEBOOT developed by Fox Network Systems, 15200 Shady Grove Road, Suite 350, Rockville Md. 20750 (301-924-2264). Once such system is described in U.S. patent application Ser. No. 07/966,081 filed Oct. 23, 1992 and assigned to assignee of the present invention, the contents of which are incorporated by reference herein. These devices, however, provide no remote video display or keyboard/mouse interface capabilities.
U.S. Pat. No. 5,153,886 to Tuttle discloses a visual display signal processing system and method used for regression testing of computer hardware and/or software applications. The system disclosed in Tuttle, however, relies upon connection to the internal video adapter circuitry and does not operate to interpret video raster signals generated by the video display adapter circuit. Furthermore, the system disclosed in Tuttle is intrusive since it requires a circuit card to be installed into a computer to be tested, and cannot be easily connected to a computing device using the existing standard interface connectors.
U.S. Pat. No. 5,084,875 to Weinberger et al. discloses a system for automatically monitoring copiers from a remote location and allowing operation of a copier from a remote location. Weinberger et al., however, does not disclose a system suitable for use in remote monitoring and control of a personal computer system or network, and further does not disclose a system which can monitor and forward video raster signals generated by a remote computer system.
U.S. Pat. No. 5,124,622 to Kawamura et al. discloses a system for remote diagnosis of a numerical apparatus. Again, however, Kawamura et al. does not disclose a system which can monitor and forward video raster signals generated by a remote computer system. Additionally, Kawamura et al. does not disclose a system for use in remote monitoring and control of a personal computer system or network.
U.S. Pat. No. 5,237,677 to Hirosawa et al. discloses a monitoring and controlling system and method for a data processing system in which report of a fault occurrence is automatically effectuated to a remotely located supervision/control system. Hirosawa et al., however, fails to disclose a system that can monitor the video raster signals generated by a remote data processing system.